Mar
22
2007

HDTV Explained in English

This is HDTV as simple as I can explain it. I recently came to the realization that I live in a fantasy world. This fantasy is that after I finally finish Grad School and become employed full-time earning a real salary that I’ll suddenly have loads of extra money to spend on expensive toys. Don’t bring me back to reality. I like where I am.

With that in mind, I’ve begun researching HDTVs. So many different signal types, so many options. Nowadays, TVs are starting to double for computer monitors and monitors are capable of doubling as TVs, so I thought I’d share the findings of my little research projects and tell you what I’ve learned about HDTV and the various ways that you can hook it up to your computer or HDTV provider.

Resolutions
There are different resolutions for HDTVs which are expressed in terms of the vertical resolution and whether the picture is interlaced or progressive. Progressive is better (smoother) and this is noticeable when things are moving quickly. Things like sports, action movies, etc. look better on a progressive screen.

As far as I can tell, the only good reason for HDTV to make up their own kinds of resolution is to try to keep it a secret that computers have been doing much higher resolutions for years. When you’re trying to translate between the two however, we need some important information.

480i and 480p: These are associated with the old-fashioned standard-def TVs (don’t be offended, that’s all I’ve got at my house too) and the never-took-off enhanced-def TVs.

720p and 1080i: Nearly every HDTV source broadcasts in one of these two resolutions. It’s a tossup as to which of these formats is better, but what was important to me was the resolution. Your TV must have a 1280×720 to display the whole picture. 1366×768 is better. If you’re TV is only capable of 1024×768 (very common in HDTVs) it will still show you the content, you’ll just be missing out on the full glory of the experience. TV sets down-convert from the higher format into the TV’s max (or native) resolution and many people never figure out that they’re missing something.

1080p: The only sources of this kind of content are Blu-Ray, HD-DVD, and computers. It’s even better than most computers are capable of handling. To display the full content of a 1080p source, you’ll have to have a screen resolution of 1920×1080.  Building TV sets that can display this resolution takes longer than the lower resolution sets, which explains why you’ll usually pay so much more for the 1080p.

Plugging In
Resolution is only one piece of the puzzle. Once you’ve got the TV, you’ve still got to plug you’re source into the TV.

HDMI: The High-Definition Multimedia Interface probably tops off the list as the simplest option. It packages your digital video and digital audio into one easy cable. The current HDMI in use (type A) is fully capable of carrying the full 1080p signal, but won’t go any higher. Future HDMI (type B) can go higher, but currently it’s not important or in use.

DVI: The Digital Visual Interface is standard on today’s computers. Single-link DVI can handle resolutions of 1920×1200 (slightly higher than the 1080p) and dual-link DVI can go as high as 3840×2400. I doubt you’ll find a TV or computer screen in existence that can handle that though. The Apple cinema displays go as high as 2560×1600, but that’s the highest I’ve ever heard.

Component Video: Like everything else in the world of computers, color is produced by mixing red, green, and blue. In order to produce a sharper picture, sometimes the video signal is split into these three colors and each color is sent over a separate cable. Component video can do all HDTV resolutions from 480i all the way up to 1080p. Historically the signal carried has been an analog signal, though digital is becoming much more popular in computers and home theaters.

Wrapping Up
If your TV doesn’t have a DVI input (many do) then you’ll have to convert your computer signal in some way in order to display it on your TV. Converting from DVI to HDMI or component video is quite simple. A cheap adapter you can pick up at any electronics store will do the job.

If you end up converting from DVI to HDMI you should realize that your audio will be lost along the way. Unless you’re plugging your computer audio into your home theater sound system, you might want to consider the component video route. Component inputs on a TV have more room for audio, so if you go that route you can still get sound and video from your computer to your TV.

This brings us to the subject of home theater audio, which I’ve also been researching, but I’ll leave that topic for another day. For more information on today’s topic, you can look below.

http://www.lcdtvbuyingguide.com/hdtv/hdtv-resolutions.shtml
http://reviews.cnet.com/4520-6449_7-6361600-1.html
http://en.wikipedia.org/wiki/Hdmi
http://en.wikipedia.org/wiki/Dvi
http://en.wikipedia.org/wiki/Component_video

At the conclusion of writing this post, I just found this article as well, which may provide some additional insight: http://forum.ecoustics.com/bbs/messages/34579/122868.html

7 Comments + Add Comment

  • [...] HDTV does not have to be as difficult as some seem to think. Just knowing a few standard terms (and what they actually mean) will make purchasing an HDTV set a more pleasurable experience. Since all broadcasting in the United States will be digital by 2009, this is a purchase most of us will have to face in the not to distant future. [...]

  • When the new digitial signals are required in 2009, will the cable hd boxes, now required for cable, be eliminated. Have heard, although not confirmed ,that only one hd/digitial signal will be transmitted over the cable(comcast as example)after the new regulations go in effect . If one has a digitial tuner built in to their tv, will an hd cable tuner box still be required to receive the HD signal or will there just be one cable box required by the cable manufacturer.? I receive all my major network HD signals from a UHF antenna and my other channels from a DISH source. At some point(after 2009) will all the signals being transmitted be in HD format whether it be cable or dish network/direct TV.?

    Bob G

  • I think that if you’ve got an HD Tuner card built into your TV set that you won’t have to have the external box. I seem to recall seeing some legislation recently that was requiring Comcast to develop a tuner card that could be plugged into TV sets rather than forcing all customers to use the external HD receivers. However, I’m certainly not the authoritative source for that kind of information.

  • Hi , i have some questions about you desing
    maybe you can give designer contacts?

  • I didn’t design the theme myself, but picked it up from somewhere. Smashing Magazine has some wonderful resources for web design. This article and this one are two that I’ve looked at recently. This theme, Internet Music, was designed by Genkisan over at Ericulous and I just adjusted the color scheme.

  • Well researched site! Can you recommend any forums I could join to learn more? Thanks

  • Unfortunately no, this was just a little research project I did on my own 2 years ago, but haven’t been keeping up really. Everything here is still true, but I haven’t been participating in the industry at all.

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